Cover interlocking preventive device

ABSTRACT

Irregularly spaced detents or protuberances are placed around near the edge of a container header in order to prevent headers from interlocking when they are nested. The forming of the protuberances is accomplished as part of other operations necessary in making the header.

United States Patent Inventor John S. Bozek Chicago, Ill.

App]. No. 832,242

Filed June 11, 1969 Patented Jan. 4, 1972 Assignee Continental Can Company, Inc.

New York, N.Y.

COVER INTERLOCKING PREVENTIVE DEVICE 1 Claim, 3 Drawing Figs.

US. Cl 220/97 R, 220/42 C lnt. Cl 365d 43/06, T 865d 51/24 Field of Search 220/97, 97 C, 97 F, 42 C, 97 R References Cited UNITED STATES PATENTS 6/1964 Davis 220/97 R 5/1968 Knize 220/42 C 9/1920 Freundt... 220/97 C UX 4/1965 Amberg... 220/97 X 4/ 1968 Silvio 220/97 FOREIGN PATENTS 10/ 1 945 Great Britain 220/97 F Primary Examiner-George E. Lowrance Attorneys-Americus Mitchell, Joseph E. Kerwin and William A. Dittmann ABSTRACT: lrregularly spaced detents or protuberances are placed around near the edge of a container header in order to prevent headers from interlocking when they are nested. The forming of the protuberances is accomplished as part of other operations necessary in making the header.

PATENTED JAN 4 i972 INVE N TOR JOHN s. BOZEK I j ATT'Y.

COVER INTERLOCKING PREVENTIVE DEVICE My invention relates to an improvement in the forming of container covers, and particularly to the forming of container covers and containers which are to be stacked.

Container covers and bottoms are stacked by nesting one within the other. This method of stacking frequently produces wedging between nested container covers, for example, and one or more container covers may be lost or destroyed because of the force necessary to pull them apart. In order to avoid this problem, partitions or separators are placed between the individual covers. Similarly, where container bottoms are stacked, separators may be placed between in dividual container bottoms. This has a great economical disadvantage because not only separators have to be added to the cost, but also the additional labor required to place these separators between products must be added to the cost. In some cases, pips and ridges have been formed on the surface of covers in order to separate them and avoid sticking between adjacent covers. However, this method has also its disadvantages because it does not prevent covers from sliding sideways.

An object of my invention is to keep the elements of containers from interlocking and to improve lateral stability.

Another object of my invention is to provide stability in the stacking of container elements without requiring additional separator sheets to hold the container elements apart.

Other objects and advantages of my invention will become apparent from the following description taken in conjunction with the accompanying drawings in which:

FIG. 1 shows a container cover having the features of my invention;

FIG. 2 shows a plan view of a pattern of the protrusions; and

FIG. 3 shows a cross section of the tooling used in forming the protrusions.

In brief, my invention comprises the forming of an indented portion on the surface of a preformed cover and/or preformed bottom of each container. Thus, spacing between headers, i.e., stacked covers or stacked bottoms, is assured.

The detents shown in FIG. I are formed by embossing deep V-shaped valleys towards the lower surface of a closure element 1. The depth of the detent or protuberance 2 determines the space between nested covers or container bottoms. The greater the depth of the protuberance, the greater the space between covers 1. This detent 2 or protuberance depth may be large or small in conformity with the amount of space which is to be used for each container cover. If the detents are equally spaced on the same circumference, the danger of interlocking is more severe than when they are spaced unequally. This is because if there were seven detents, then at every 51 space, the detents of covers would match perfectly and by falling into each other would interlock much tighter.

In order to avoid protuberances being regular around a clo sure element or container lid, the protuberances are irregularly spaced so that the protuberances of cover 1 above do not match the protuberances of the cover below and thus the problem of protuberances wedging is avoided when the closures or headers I are stacked. The protuberances shown in FIG. 2 are each located a different distance from the other and spacing is asymmetrical. The exemplary spacing shown is as follows: 33; 70; 39; 58; 51; 45; and 64. In this way, the chances of protuberances falling into the reverse sides of the protuberances of other stacked headers is minimized. Further, if the protuberances do match up on container lids, for example, there is a limited protuberances penetration because the outside diameter of a protuberances is greater than its inside diameter by twice the thickness of the material from which the protuberance is formed. A circular ridge 3 and groove 4 may be formed around the cover a short distance inside the protuberances. This ridge and groove may match with a ridge and groove on the bottom of the container. In this way, when the filled containers are stacked, the containers do not shift relative to each other.

The operation of the forming apparatus shown in FIG. 3 is as follows:

This forming apparatus performs three operations at one station. The three operations are trimming the preformed lid, hemming the edge of the lid, and forming protuberances along the inside of the lid. The operations described above are accomplished as follows:

The preformed lid 1 is placed on the lower die 5 and the upper die 6 descends toward the preformed lid. The clamping ring I2 is the first of the moving elements to contact the preformed lid and to lock it in place at ridges 3 and 13 to prevent any distortion of the panel during forming of the detents. Next, the protrusion forming element I4 descends against the cover, it forces out a protrusion 2 as shown in FIG. 3. While the upper die progressively moves downward, trimming is accomplished as the outer, upper die element 7 slides by the inner hemming element 8 and cuts the cover skirt 9 equally around its edges. The outer cover material 10 is caught between the upper die element 7 and the lower die element 11 at this time. Thus, after the step of trimming, there is a clean, evenly cut edge around the preformed cover 1. Thus, after the upper die and its auxiliary moving elements 7, and 12, have completed their downward movement, the cover 1 has been trimmed to a unifonn size around its edge, and protrusions have been formed in the approximate locations shown in FIG. 2. After the upper moving dies have completed their operation, and have reached their lowermost position, the upper moving dies are withdrawn and the lower moving die 11 starts upward. As the inner die 8 of the two lower moving dies encounters the skirt 9 of the cover, the skirt is rolled upward to provide a flat hem 9 for the cover. This flat hem 9 has the same height all around because in the trimming operation, the trimmed edge is cut to equal length. As is readily appreciated, after the lower movable elements have completed their part of the cycle, the cover has been trimmed, hemmed, and separation protrusions have been formed in the cover. Thus, three operations are performed with one set of dies and at one station.

As may readily be appreciated, the forming of the protrusions 2 in a metal cover is one of a sequence of operations which starts with the cutting of a cover blank out of a flat piece of stock. The next step is forming the metal blank into a hat-shaped cover, with an uneven straight flange, trimming the edge, forming protrusions, and rolling a hem around the edge to avoid cutting in handling. when the final operation is completed, the cover is ready for stacking and transportation.

Among the advantages of this invention are that the formed covers do not shift relative to each other, the stacked covers do not stick to each other, and the number of dies and stations needed for fonning is reduced.

Although specific embodiments have been shown and described, it is with full awareness that many modifications thereof are possible. The invention, therefore, is not to be restricted except by the prior art and by the spirit of the appended claims.

What is claimed is:

l. A container header comprising:

a short, circular, flared skirt having a bottom edge and forming a lateral surface of a container header,

a discontinuous ridge means formed on the upper surface of said container header;

seven protuberances provided on the lower surface of said header, located at radially spaced intervals of 33, 39, 58, 51, 45 and 64 and said protuberances are of a depth such that the protuberances extend to a level above the plane defined by the edge of said flared skirt whereby when said headers are stacked, said protuberances on said lower surface fall upon said discontinuous ridge means on said upper surface to provide a spacing means between headers and prevent interlocking of one header to another,

a circular ridge on the upper surface of the header and having formed on its inner side a depression between said first circular ridge and said discontinuous ridge means and having said skirt as its outer side, whereby the inside of said skirt of a first header dovetails with the outside of the skirt of the circular ridge of a second header just below it to prevent the headers from shifting relative to each other when a plurality of headers are stacked upon each other one above the other. 5

i t t i t 

1. A container header comprising: a short, circular, flared skirt having a bottom edge and forming a lateral surface of a container header, a discontinuous ridge means formed on the upper surface of said container header; seven protuberances provided on the lower surface of said header, located at radially spaced intervals of 33*, 70*, 39*, 58*, 51*, 45* and 64* and said protuberances are of a depth such that the protuberances extend to a level above the plane defined by the edge of said flared skirt whereby when said headers are stacked, said protuberances on said lower surface fall upon said discontinuous ridge means on said upper surface to provide a spacing means between headers and prevent interlocking of one header to another, a circular ridge on the upper surface of the header and having formed on its inner side a depression between said first circular ridge and said discontinuous ridge means and having said skirt as its outer side, whereby the inside of said skirt of a first header dovetails with the outside of the skirt of the circular ridge of a second header just below it to prevent the headers from shifting relative to each other when a plurality of headers are stacked upon each other one above the other. 